Unless the contractor is willing to put in writing a "not to exceed" price, I've never put any faith in build estimates. I'd expect a professional to be able to give a rough estimate based on experience and scope, as well as clear communication as the project progresses. Rough estimate meaning accurate withing something like 20-30%, not a detailed breakdown by ever project and material expense.
I try to do the same in software projects. Estimating projects by hours is impossible, fibonnaci numbers are a meaningless abstraction, and spending time each sprint to discuss how it went, what the next sprint plan is and estimate every task is a waste of time.
What I can say is whether a task looks like something that could be done in an afternoon, a few days, a few weeks, or multiple months. Accuracy there comes with experience, but no one gets better by chopping the calendar year into 2 week intervals and pouring a ton of process all over it.
I try to do the same in software projects. Estimating projects by hours is impossible, fibonnaci numbers are a meaningless abstraction, and spending time each sprint to discuss how it went, what the next sprint plan is and estimate every task is a waste of time.
What I can say is whether a task looks like something that could be done in an afternoon, a few days, a few weeks, or multiple months. Accuracy there comes with experience, but no one gets better by chopping the calendar year into 2 week intervals and pouring a ton of process all over it.